1. Field of the Invention
It is well recognized in the field of Urology that persons lose control of their urinary function. This loss of control may be temporary or permanent, depending upon the cause of the loss of urinary function. Temporary loss may be caused by a disease entity which is curable by medical or surgical treatment, whereas permanent loss of control may be caused by an incurable disease entity or physical trauma resulting in partial or total paralysis of the muscles which cause normal urination. The bladder is a dome shaped container with muscular walls and which accepts urine from the kidneys for temporary storage. During normal voluntary urination, the muscles in the bladder wall contract and simultaneously the sphincter muscle surrounding the opening in the bladder which communicates with the urethra relaxes so that the urine stored in the bladder is released into the urethra and expelled from the body.
The causes for loss of normal voluntary control of the urination process are manifold and the consequences are indeed severe. If urine cannot be periodically expelled from the bladder, the urine becomes stagnant and bacteria multiply at an exceedingly rapid rate, resulting in infection of the bladder. Chemical changes in the urine due to the infection cause painful urination and can also cause general dibilitation of health. If, after infection occurs, the urine retention is still permitted to continue for any considerable length of time beyond normal voluntary urination frequency, ascending infection can occur, that is the infection in the bladder spreads to the ureters and to the kidneys, thereby causing still more serious consequences, such as failure of one or both of the kidneys to function. If the kidneys do not function to cleanse the blood of impurities and form urine, uremia results and death occurs in the absence of the availability of recently developed artificial kidney machines. If, on the other hand, the kidneys continue to function and fill the non-draining bladder with urine, the bladder can burst, thereby emptying the bacteria laden urine into the abdominal cavity. The usual result of this is peritonitis, which is an inflammation of the peritoneum, the membrane that lines the abdominal cavity, and the results of inflammation of this membrane are always serious. The time between the occurrence of acute peritonitis and death may be only a matter of a few hours to a few days depending upon the severity of the infection. Septicemia, an infection of the blood, is another serious consequence of excessive retention of urine in the bladder, since the bacteria in the bladder, ureters and kidneys invades the blood through the minute blood capillaries in these organs.
Obviously other complications, bodily disorders and disfunctions and serious consequences, too numerous to mention herein, can result from failure of proper urination. It is obvious that constant periodic drainage of the bladder to eliminate urine and other body waste material is essential not only to good health but to maintaining life itself.
Techniques of treatment for loss of normal voluntary control of the urination process are relatively few in number. Depending on the nature of the cause, a super-pubic technique involving surgery may eliminate the drainage problem in some circumstances. Since surgery is involved, this treatment is traumatic and severe, and is utilized only when absolutely necessary. Drug therapy is effective in some cases to promote drainage of the bladder, but due to the relatively few causes of loss of voluntary control which will respond to drugs and the ever presence of undesirable side effects, drug therapy is considered to be a relatively ineffective method of dealing with the problem.
2. Necessity for Practice of Invention
Since the loss of voluntary control over the urinary function is typically a secondary effect caused either by disease or trauma, it has become a well established medical practice to relieve the urinary drainage problem mechanically by means of the process of catheterization. If the primary cause of the loss of voluntary urination control is from a curable disease, the catheterization process is maintained on a temporary basis only for so long as necessary until voluntary control returns. If the cause of loss of control is permanent, as in the case of paralysis such as with paraplegics and quadriplegics, the catheterization process must be maintained on a permanent basis in order to maintain life.
In the catheterization process, a tube or catheter is inserted into and through the urethra until the remote or distal end is located within the bladder, usually being disposed just past the sphincter muscle at the juncture of the bladder with the urethra. The near or proximal end of the tube remains outside of the body and there is thus provided a path or channel through which urine in the bladder can drain as the need arises. Once a catheter has been passed through the urethra and inserted into the bladder, it is generally necessary, in connection with the disease and trauma conditions described above, to have the catheter retained in the urinary tract with the distal end of the catheter in the bladder, such retention being in the order of several days to several weeks without removal. Catheters which are designed for use a function are called urinary retention catheters and are typically provided by including an inflatable balloon at the distal end of the catheter which is deflated during insertion of the catheter and which is inflated by passing a fluid, typically water or saline solution through a passage within the catheter, called an inflation lumen. Thereafter, fluid from the bladder drains through the main passage of the catheter, called the drainage lumen.